CFHTLS optical photometry has been used to study the galaxy luminosity functions of 14 X-ray selected clusters from the XMM-LSS survey. These are mostly groups and poor clusters, with masses (M_{500}) in the range 0.6 to 19x10 ^{13} M_solar and redshifts 0.05-0.61. Hence these are some of the highest redshift X-ray selected groups to have been studied. Lower and upper colour cuts were used to determine cluster members. We derive individual luminosity functions (LFs) for all clusters as well as redshift-stacked and temperature-stacked LFs in three filters, g', r' and z', down to M=-14.5. All LFs were fitted by Schechter functions which constrained the faint-end slope, alpha, but did not always fit well to the bright end. Derived values of alpha ranged from -1.03 to as steep as -2.1. We find no evidence for upturns at faint magnitudes. Evolution in alpha was apparent in all bands: it becomes shallower with increasing redshift; for example, in the z' band it flattened from -1.75 at low redshift to -1.22 in the redshift range z=0.43-0.61. Eight of our systems lie at z~0.3, and we combine these to generate a galaxy LF in three colours for X-ray selected groups and poor clusters at redshift 0.3. We find that at z~0.3 alpha is steeper (-1.67) in the green (g') band than it is (-1.30) in the red (z') band. This colour trend disappears at low redshift, which we attribute to reddening of faint blue galaxies from z~0.3 to z~0. We also calculated the total optical luminosity and found it to correlate strongly with X-ray luminosity (L_X proportional to L_OPT^(2.1)), and also with ICM temperature (L_OPT proportional to T^(1.62)), consistent with expectations for self-similar clusters with constant mass-to-light ratio. We did not find any convincing correlation of Schechter parameters with mean cluster temperature.
The XMM-LSS catalogue: X-ray sources and associated multiwavelength data. Version II
我们提出了最终发布的多波长XMM-LSS数据集，覆盖了11.1平方度的整个调查区域，X射线数据处理与最新的XMM-LSS管道版本。本出版物取代Pierre et al. 2007年，《第一个五度角》出版。我们提供了X射线源列表中的常规能量带（0.5-2和2-10千电子伏），共6721个对象在深全曝光目录和5572在10千秒限制的一个，以上的检测可能性15至少在一个波段。我们还提供多波长目录，将我们的列表与IR、NIR、光学和UV目录相互关联。常规数据产品（X射线FITS图像、CFHTLS和SWIRE缩略图）与我们在米兰的可交互查询的数据库一起提供，而目录的静态快照将在最后验收完成后立即提供给CDS。
We present a comparison of two samples of z>0.8 galaxy clusters selected using different wavelength-dependent techniques and examine the physical differences between them. We consider 18 clusters from the X-ray selected XMM-LSS distant cluster survey and 92 clusters from the optical-MIR selected SpARCS cluster survey. Both samples are selected from the same approximately 9 square degree sky area and we examine them using common XMM-Newton, Spitzer-SWIRE and CFHT Legacy Survey data. Clusters from each sample are compared employing aperture measures of X-ray and MIR emission. We divide the SpARC…
We point out a new possibility to determine the average redshift distribution of a large sample of gravitational wave standard sirens, without spectroscopic follow-ups. It is based on the cross correlation between the luminosity-distance space large scale structure (LSS) traced by standard sirens, and the redshift space LSS traced by galaxies in preexisting electromagnetic wave observations. We construct an unbiased and model independent estimator $E_z$ to realize this possibility. We demonstrate with BBO and Euclid that, $0.1\%$ accuracy in redshift determination can be achieved. This method …
Future gravitational wave (GW) observations are capable of detecting millions of compact star binary mergers in extragalactic galaxies, with $1\%$ luminosity-distance ($D_L$) measurement accuracy and better than arcminute positioning accuracy. This will open a new window of the large scale structure (LSS) of the universe, in the 3D {\bf luminosity-distance space (LDS)}, instead of the 3D redshift space of galaxy spectroscopic surveys. The baryon acoustic oscillation and the AP test encoded in the LDS LSS constrain the $D_L$-$D^{\rm co}_A$ (comoving angular diameter distance) relation and there…
The X-ray luminosity function of distant (3<z<5.1) unabsorbed quasars has been measured. A sample of distant high-luminosity quasars ($10^{45} \leq L_{{\rm X},2-10} < 7.5 \times 10^{45}$ erg/s in the 2--10 keV energy band) from the catalog given in Khorunzhev et al. (2016) compiled from the data of the 3XMM-DR4 catalog of the XMM-Newton serendipitous survey and the Sloan Digital Sky Survey (SDSS) has been used. This sample consists of 101 sources. Most of them (90) have spectroscopic redshifts $z_{spec}\geqslant 3$. The remaining ones are quasar candidates with photometric redshift estimates $…
GW number count can be used as a novel tracer of the large scale structure (LSS) in the luminosity distance space (LDS), just like galaxies in the redshift space. It is possible to obtain the $D_L-D_A$ duality relation with clustering effect. However, several LSS induced errors will contaminate the GW luminosity distance measurement, such as the peculiar velocity dispersion error of the host galaxy as well as the foreground lensing magnification. The distance uncertainties induced from these effects will degrade the GW clustering from a spectroscopic-like data down to a photometric-like data. …
We present a fully relativistic framework to evaluate the impact of stochastic inhomogeneities on the prediction of the Hubble-Lemaître diagram. In this regard, we relate the fluctuations of the luminosity distance-redshift relation in the Cosmic Concordance model to the intrinsic uncertainty associated to the estimation of cosmological parameters from high-redshift surveys (up to z = 4). Within this framework and according to the specific of forthcoming surveys as Euclid Deep Survey and LSST, we show that the cosmic variance associated with the measurement of the Hubble constant will not exce…
The XMM-Newton Wide field survey in the COSMOS field: redshift evolution of AGN bias and subdominant role of mergers in triggering moderate luminosity AGN at redshift up to 2.2
